BANGKOK — Delivering an unusual public rebuke, former Gov. Bill Richardson of New Mexico resigned Wednesday from a Myanmar advisory board on the Rohingya crisis, calling it a pro-government “cheerleading squad” and chastising the country’s civilian leader, Daw Aung San Suu Kyi, whom he has long considered a friend.

“She has developed an arrogance of power,” Mr. Richardson said by telephone during a layover in Tokyo on his way back to New Mexico from Myanmar. “I’ve known her a long time and am fond of her, but she basically is unwilling to listen to bad news, and I don’t want to be part of a whitewash.”

Nearly 700,000 Rohingya Muslims have fled Rakhine State in western Myanmar for Bangladesh over the past five months. Ms. Aung San Suu Kyi, a Nobel Peace Prize laureate, has declined to speak out forcefully against the Myanmar military’s campaign of execution, rape and arson against the Rohingya, which the United Nations and United States have labeled ethnic cleansing.

Mr. Richardson said that Ms. Aung San Suu Kyi had “exploded” at him when he raised the detention of two Reuters journalists, U Wa Lone and U Kyaw Soe Oo, who are facing up to 14 years in prison under the country’s Official Secrets Act after they began investigating a mass grave of Rohingya in northern Rakhine.

“Her face was quivering, and if she had been a little closer to me, she might have hit me, she was so furious,” Mr. Richardson said.

Doctors Without Borders estimates that at least 6,700 Rohingya in Myanmar met violent deaths in a single month last year. Yet local investigations into the crisis, which began after Rohingya insurgents attacked Myanmar security posts last August, claim that not a single Rohingya civilian was harmed by the Tatmadaw, as the Myanmar military is known.

Ms. Aung San Suu Kyi has set up at least half a dozen commissions, panels and boards dedicated to the turmoil in Rakhine, including the Advisory Commission Board on Rakhine State, to which Mr. Richardson was named.

Kofi Annan, the former United Nations secretary general, chaired another panel, which was formed after an earlier military crackdown on the Rohingya in 2016. His commission recommended that the government of Buddhist-majority Myanmar allow unfettered humanitarian access to the epicenter of violence in northern Rakhine.

To this day, however, the Myanmar government has refused to allow United Nations investigators and the international media to freely visit northern Rakhine. Aid groups have been similarly stymied. Last month, Yanghee Lee, the United Nations special rapporteur on Myanmar who has been a vocal critic of the military crackdown, was denied a visa to the country.

Mr. Richardson, a former United Nations ambassador under President Bill Clinton, has a reputation as a diplomatic troubleshooter. He said last week en route to Myanmar that during his visit he intended to secure the release of the Reuters journalists, who were seized in December.

“One of my objectives in joining the advisory board was to be helpful and try to sort out real, long-term policy solutions,” Mr. Richardson said. “But I discovered that this board was being used as a cheerleading squad for the government.”

Mr. Richardson said he had been “very shocked” by how Ms. Aung San Suu Kyi and other board members had disparaged human rights groups, the United Nations and international media organizations over how the Rohingya disaster had been presented to the world.

He was particularly critical of the advisory board’s chairman, Surakiart Sathirathai, a Thai politician who, Mr. Richardson said in a statement, had sought to “avoid the real issues at the risk of confronting our Myanmar hosts.”

The board’s agenda, Mr. Richardson said in the statement, was “devoid of any meaningful engagement with the local communities in Rakhine, whose people the advisory board is meant to serve.”

Mr. Surakiart could not immediately be reached for comment.

A spokesman for Myanmar’s government, U Zaw Htay, said that Mr. Richardson did not understand the “rules and regulations” of the board’s meeting with Ms. Aung San Suu Kyi and accused him of overstepping his mandate.

“He needs to understand clearly that he is supposed to give advice only about the Rakhine issue, not everything about Myanmar,” Mr. Zaw Htay said. “He cannot say whatever he wants to say.”

The departure of Mr. Richardson could deeply damage the credibility of the advisory board. Mr. Richardson was among a powerful coterie of global leaders, human rights advocates, journalists and diplomats who had championed Ms. Aung San Suu Kyi for her principled stand against Myanmar’s military junta, which kept her under house arrest for more than a decade and a half.

But ever since Ms. Aung San Suu Kyi entered a power-sharing agreement with the military in 2016, she has grown distant from her international supporters. She has refused to meet with some of her former advocates and complained about a “huge iceberg of misinformation” related to the Rohingya.

Some of Ms. Aung San Suu Kyi’s closest advisers are now former military men. She spends much of her time in Naypyidaw, the cloistered, largely empty Myanmar capital that was built by the generals to remove themselves from the thrum of life in Yangon, the nation’s largest city.

“She is in a bubble where she has people always telling her how great she is,” Mr. Richardson said. “She’s in the classic situation that politicians and leaders get themselves in when they don’t want to listen to bad news and they have psychopaths around them who don’t want to tell them the real situation.”

A spokeswoman for Mr. Richardson said later that he had meant “sycophants,” not “psychopaths.”

While certain individuals, like her fellow Nobel Peace Prize laureates Desmond Tutu and Malala Yousafzai, have publicly censured Ms. Aung San Suu Kyi, others have cautioned that her authority is constrained by a military-drafted Constitution that keeps most of Myanmar’s power in the hands of the Tatmadaw.

“I hope this will be a wake-up call for her,” Mr. Richardson said of his resignation. “But I sort of doubt it. I think she has added me to her enemy list, which includes the United Nations, the international media, human rights groups, Nobel laureates.”